Steering knuckle

ABSTRACT

A steering knuckle structure that makes it possible to produce a light weight steering knuckle from a light metal alloy with a high degree of rigidity. A bracket for fixing a telescopic strut is provided at a vertically extending bracket wall which is supported by a bridge and wherein the area between the bridge and the bracket wall is open in a peripheral direction of the hub of the steering knuckle.

The invention relates to a steering knuckle with a hub for receiving awheel bearing and with a bracket for fixing a control arm, especially atelescopic strut, wherein the bracket is formed on an arm projectingfrom the hub.

The general problem in such a steering knuckle is that on the one handit should be very light, so that the non-dampened mass of the wheelsuspension system is as small as possible and that on the other hand ahigh rigidity has to be provided, as all the forces for the longitudinaland transversal deceleration of the vehicle and of course the weight ofthe vehicle act on to it. The compromise realized up to now consists ina steering knuckle, which is made from a steel casting or iron casting.

One example for this is disclosed in DE-OS 26 24 704 A1. The casting hasa hub, from which several arms project. One arm extends upwards and endsin a bracket, on which the lower end of the telescopic strut is fixed bymeans of two pins. To achieve the required rigidity the arm has aV-shaped cross-section.

DE 43 13 624 A1 discloses a steering knuckle made by a metal punchingmethod. The advantage, named, compared to the casted or forged steeringknuckle is the achievable weight reduction. The steering knuckle issubstantially U-shaped, wherein the open side points to the vehicle. Atthe lower portion it is formed square for receiving a bearing, thatmeans the legs abut approximately perpendicular the bottom of the U. Theupper portion forms an arm for connecting a transverse control arm andhas a semicircular cross-section. A recipient mounted there, for theball pin of the transverse control arm has correspondingly the form of ahalf disc and is retained by a pin between the legs.

A similar embodiment can be taken from DE 195 33 315 C1. In thisembodiment the open side of the U-shaped steering knuckle is closed by atab and therefore is additionally reinforced. Therefore, an arm closedon all sides, is achieved.

It has been already proposed, inter alia in DE 196 53 542 A1, to usesteel or iron-light weight metal alloys, such as aluminum. This materialhas on the one hand the advantage to be light, but also has thedisadvantage of not being sufficiently rigid. Therefore, in theunexamined publication it is proposed, that the core of the steeringknuckle is formed from light weight metal of higher strength as a hollowbody with defined wall-thickness. Furthermore, it is clearly visible,that the manufacturing processes, necessary, are quiet cumbersome.

Therefore, the invention is based on the object, to provide a steeringknuckle as light as possible, preferably made from a light metal alloy,which is simple to manufacture and having a sufficient strength a goodrigidity.

In a first preferred embodiment, the steering knuckle is formed in sucha way that the arm is formed by an approximately perpendicular bracketwall on whose side facing toward the vehicle the bracket is formed, andthat a bridge extends between the outer end of the bracket wall and thehub, wherein the space between the bracket wall and the bridge is opento the side, i.e., open in the circumferential direction of the hub.

It has been found that because of this arrangement a high strength canbe achieved, which especially can be referred back to the fact, thatthis arrangement is open in the circumferential direction compared to anarrangement, in which the arm has a U-shape and is open towards thevehicle. Furthermore, it has been found that the fatigue durability isincreased and a compact design can be realized.

A second preferred embodiment consists of a hub that merges on thecontrol arm side in a partial sleeve, wherein the bracket wall extendsfrom the free end of the partial sleeve. Furthermore, one of the opensides of the chamber can be closed by a transverse wall, wherein thiswall continues in a partial face on the hub, on which a bracket forfixing a brake caliper is provided.

Advantageously, the transverse wall is inserted in such a way, that itsclosed side extends in the driving direction, so that the arm thusformed is open to the rear in respect to the driving direction.

To be able to attach a steering rod to the steering knuckle, a supportwall extending approximately horizontal is formed at the lower side ofthe hub or the partial sleeve, on which free end a fixing eye for thesteering rod is provided. An extension of the bracket wall extends alongthe partial sleeve and joins perpendicularly the support wall.

Following, a detailed description by means of an embodiment will begiven with reference to the drawings.

FIG. 1 shows a perspective view onto the wheel side of the steeringknuckle and

FIG. 2 shows a perspective view onto the control arm side of thesteering knuckle.

The wheel side designates the side of the steering knuckle, on which inthe mounted condition a wheel, retained by the wheel bearing, isprovided, while the control arm side designates the side, facing thevehicle. The structure of the steering knuckle will be describedstarting from a hub 1. All the components, described in the following,are, as far as they are represented in the drawings, formed as a singlecasting in the mounted state.

The hub 1 is formed by a ring serves for receiving a bearing for a wheelaxle. On the side of the control arm, the hub 1 is extended axially by apartial sleeve 2, which extends in the clockwise direction from sixo'clock up to approximately two o'clock, when looking onto the side ofthe control arm (FIG. 2). At the lower end the height of the partialsleeve is still small and only reaches its maximal amount atapproximately nine o'clock. At the upper end, the slightly conicallyexpanded partial sleeve merges in the manner of an arc with an end edge3. On the circumference of the hub 1, three pin bores 4 for fixing thewheel bearing are distributedly provided. As far as these are providedin the area of the partial sleeve, recesses for the insertion of thepins are provided in the sleeve wall.

Starting from the free end of the partial sleeve 2 a bracket wall 5extends with a base, which extends from around nine o'clock to twoo'clock, i.e. up to the end edge 3, perpendicularly upwards, on whichcontrol arm side a bracket 6 is formed. The left side of the bracketwall 5, according to the FIG. 2, extends in a convex arc 7 while theright side ends in an approximately perpendicularly extending endingedge 8. The bracket 6 is formed by two webs 9, which extend parallel andperpendicular to the bracket wall and which upper and lower ends expandto a half round 10. The portion between these expansions is formed largeand has transverse bores 11 through which the pins for fixing atelescopic strut are passed through, respectively.

The bracket wall 5 is supported by a bridge 12 on the side of the wheel.This bridge starts at the hub 1 with a width, correspondingapproximately to the diameter of the hub and extends in a 90°-arc to theupper end of the bracket wall 5. Its width is reduced until itcorresponds to the width of the bracket 6 in the transition to thebracket wall. In this way a space is formed which is delimited downwardsby the partial sleeve 2, towards the wheel by the bridge 12 and to thecontrol arms by the bracket wall 5.

The opening on the side, extending in the driving direction, of thisspace is closed by a transverse wall 13, which is clearly visible inFIG. 2. The other side remains open (see FIG. 1).

The transverse wall 13 is continuous with the end edge 8 of the bracketwall 5 and with the end edge 3 of the partial sleeve 2. Furthermore, theouter wall face adjoins flush a bent portion face 14 on the outer sideof the hub 1, on which a bracket 15 for fixing a brake caliper is fixed.A support wall 16, which projects laterally and on which free end afixing eye 17 for a control arm is formed, extends approximatelytangentially to the lower end of the partial sleeve 2. The support wall16 extends substantially horizontal and is retained by a strut 18extending perpendicularly and which represents an extension of thebracket wall 5. This strut 18 adjoins approximately perpendicular thesupport wall 16 and supports this support wall from above.

Below the hub 1 a long extended and perpendicular pedestal wall 19extends transversely, which with its one end supports the support wall16 from below and with its other end extends substantially up to thebracket 15 for the brake caliper. At the side of the control arm of thepedestal wall 19 two bearing eyes 20 are formed, between which the lowertransverse control arm of a wheel suspension system is held. On the sideof the wheel of the pedestal wall 19 the bearing eyes 20 are supportedby two supports 21, which are formed between the hub 1 and the pedestalwall 19 and extend towards the two lower pin bores 4.

What is claimed is:
 1. A steering knuckle comprising: a hub adapted forreceiving a wheel bearing; a bracket formed on a bracket wall projectingapproximately tangential to the hub; and a bridge extending from the hubto the bracket such that a space between the bracket and the bridge isopen.
 2. The steering knuckle according to claim 1, wherein the bracketwall extends circumferentially from at least a portion of the hub. 3.The steering knuckle according to claim 2, wherein the bridge extendsfrom the hub to the bracket wall.
 4. The steering knuckle according toclaim 2, wherein the hub extends cylindrically along the bracket wall toform a partial sleeve, and wherein the bracket wall adjoins an end ofthe partial sleeve.
 5. The steering knuckle according to claim 4,wherein the space on one side is closed by a transverse wall, andwherein an edge of the partial sleeve adjoins a lower end of thetransverse wall.
 6. The steering knuckle according to claim 5, whereinthe transverse wall continues in a partial face adjacent the hub tofurther support a caliper bracket adapted for affixing a brake caliperthereto.
 7. The steering knuckle according to claim 4, furthercomprising a supporting wall at a lower end of the partial sleeve whichextends tangentially to the side and at an outward end of which isformed a fixing eye.
 8. The steering knuckle according to claim 7,wherein the bracket wall extends downward into a strut whichsubstantially perpendicularly abuts the supporting wall.
 9. The steeringknuckle according to claim 7, further comprising at the lower end of thepartial sleeve a bearing eye wherein between the bearing eye and thefixing eye extends a base wall below the supporting wall andperpendicularly to the supporting wall.
 10. The steering knuckleaccording to claim 1, wherein one end of the bridge that is adjacent thehub has a width which substantially corresponds to a diameter of thehub, and another end of the bridge that is adjacent the bracket has awidth which substantially corresponds to a width of the bracket.